1. Field of the Invention
The present invention relates generally to power supply circuits and more particularly, to voltage regulator systems for use in power supply systems.
2. Background of the Invention
Multi-phase regulators are commonly used in generating a single output voltage. For conventional multi-phase systems, a common control circuit drives several out-phased power circuits. The power stages typically consist of several chokes connected to a single section of output capacitors. The benefits of the conventional multi-phase design is the reduction of both input reflected ripple currents and output ripple current in the output capacitor resulting from the displaced phasing of the choke currents. In this type of arrangement, the output voltage is normally fed back into the master pulse width modulation (PWM) controller. In turn, the PWM controller compensates the loop and distributes a pulse width modulated signal out-phased to each of the several output power stages over multiple lines.
As discussed above, in comparison to single-phase systems, multi-phase regulators have a low output capacitor ripple and low input reflected ripple current. Unfortunately, conventional multi-phase regulators also have a number of disadvantages. Conventional multi-phase systems are limited to a single common input voltage and a single common output voltage. Because conventional multi-phase systems include a multi-phase PWM controller that controls multiple slave power stages, these systems also require multiple control lines running from the controller to the slave power stages. Moreover, the phase location is fixed and is not adjustable from the master controller.
In view of the foregoing, it is believed that a need exists for an improved multi-phase regulator system that overcomes the aforementioned obstacles and deficiencies of currently-available multi-phase regulator systems. More particularly, a need exists for a flexible multi-phase regulator system for use in power supply circuits.